1. Field of the Invention
The present invention pertains to a cemented carbide which exhibits excellent toughness and wear resistance and is suitable for use in solid end mills, solid drill bits and wire members.
2. Prior Art
Heretofore, print pins of a dot printer, solid end mills or solid drill bits have often been made of WC-based cemented carbide since high wear resistance is required. Such conventional cemented carbide includes a hard dispersed phase composed of tungsten carbide and a binder phase composed of 4 to 20% by weight of one or both metals of cobalt and nickel. In some cases, the hard dispersed phase further contains 0.1 to 40% by weight of one or more of compounds selected from the group consisting of carbides of metals in Groups IVa, Va and VIa of the Periodic Table other than tungsten, nitrides of metals in Groups IVa and Va of the Periodic Table and solid solution of two or more of these carbides and nitrides.
Although the prior art cemented carbides as mentioned above have been superior in wear resistance, they have been inferior in toughness, being susceptible to breakage in actual use. This has been especially the case when the cemented carbides are used with apparatuses developed in recent years wherein requirements for their performance are getting severe in order to achieve a higher speed operation as well as a higher performance.